The present invention generally relates to spooling and winding machinery, and more specifically to a spooling method and apparatus for continuously winding a continuous filament on reels with accessible long inside ends.
It is conventional for wire to be taken from a drawing machine or an extruder and continuously spooled on a pair of associated reels. See, for example, U.S. Pat. Nos. 2,763,442; 3,086,721; 3368,765 and 4,119,278, all of which have been assigned to Syncro Machine Company of Perth Amboy N.J. As will be appreciated, it is undesirable for the wire-drawing machine or extruder to be shut down to transfer the wire feed from a filled reel to an empty one. Therefore, means have been devised to automatically shift the wire from a full reel to an empty one while the wire-drawing machine or extruder remains in operation with minimum disruption.
In a variety of applications of spooled wire, it is frequently desirable that both the starting (or inside) and terminal (or outer) ends of the wire of the full reel be readily accessible prior to unwinding. This simplifies testing of the wound reels and "downstream" processes, since ends can be joined to assure continuous operation. For this purpose, it is preferred that the inside wire end has a desired pre selected length, typically 3-10 feet so as to facilitate such a process.
Virtually all of the devices which have hitherto been proposed for providing a long free inner-end on a reel uses some variations of a false coiling core, either a separate auxiliary spool, separate from the main core, or a structure which is build into the flanges of the main winding core. In many of the prior art spooling arrangements, a dummy spool is used adjacent to a main spool and the wire must go over the flanges when the long end is formed. This frequently results in an instantaneous change in the velocity with a resultant increase in the tension of the wire as the wire crosses over the flange from one diameter to the other. Such changes in tension and abrupt discontinuities in the movements of the wire often creates elongation and breakage of the wire. As objectionable as such deformations and stresses are for conventional wires or cables, they become intolerable in connection with fiber optic cables which have characteristic parameters which are particularly sensitive to bending, stretching and other deformations.
At relatively high speeds of feeding of a filament, such as a wire or cable, even one second may represent many feet of movement. Even small errors, therefore, in the timing of feeding wire onto the false or dummy spool can create many feet of unnecessary and undesired wire on the long end which has to be cut off and discarded as scrap.
For the aforementioned spoolers described in the aforementioned patents, the lengths of the inside long ends can be controlled somewhat better as the speed of the drawing or extrusion line is reduced during the period that the long ends are produced. However, this may significantly and adversely affect the productivity of the line since one must not only consider the time taken to slow down the spooler but also the time to bring the entire line back to its normal operating speed.
Also known are continuous operation stranding reels normally used for spooling bare wire. Such reels typically have a generally radial groove on the inside surface of the reel flange. However, such internal slot does not produce a long end. Other reels that are used to produce long ends run the filament generally radially along the inside surface of the reel flange. However, such radial filament portion and subsequent turns on the reel press against each other, and the radial portion or the abutting turns or both are compressed or knicked. This is a particularly serious problem in connection with optical cables or filaments since their optical properties are very sensitive to geometrical dimensions and configurations.
Other disadvantages of the prior art spoolers include the fact that they frequently scratch the wire, particularly as the wire is guided over the reel flanges between the main and the dummy spools. Additionally, the spoolers of the type under discussion cannot normally be used, for example, when winding aluminum or hard filament materials. The movement of such hard filaments over the flange, as suggested above, and change in the velocity of the wire, can result in the breakage of the wire.
The long ends are used not only for attachment to a previous length of cable in a continuous process but are also used to conduct measurements of the cable on the wound reels, using both ends of the wire or cable. Any damage to such wire, cable or filament which is reflected by abnormal readings may require that the entire length of cable on the reel be discarded. The free ends, whether long or short, are, therefore, critical and must be safeguarded during the spooling operation, particularly if such cable includes optical fibers.